Barty and Dellacqua have been one of the tour's form teams during the second half of the year, but in front of a boisterous Beijing crowd they were edged out, 64 64.
For Zheng, victory tasted particularly sweet after a disappointing showing against the Australians at last month's US Open. "When I played against them at the US Open, I have to be honest, I had really bad performance on that day," Zheng said of her 62 62 defeat alongside Sania Mirza in the last four in New York. "But I told my partner today that I would definitely play better!
"That match at the US Open was the first time I'd played them, and because of it we were actually fully prepared in terms of tactics; we had a lot of practice, particularly dealing with their topspin and coming into the net, which helped us make it today."
In the end, it was just a few points here and there that separated the teams, with breaks for Chan and Zheng at the start of the first and end of the second proving decisive.
"I think we were very aggressive on the court today," Zheng added. "On the very crucial points we had more control than them, and although it was very close in the end I think we deserved it."
Alongside former partner Yan Zi, Zheng was a runner-up in Beijing in 2005 and believes the tournament has played a pivotal role in Chinese tennis' current boom. "Ten years ago, most Chinese players did not have a very high ranking and would have to go through the qualifying to play at the big events.
"But for our local tournaments, like in Beijing, we were given wildcards, which gave us a very good opportunity to play with the top level players. This tremendously improved the development of Chinese players and its popularity as well - everybody is looking for tickets and this year we sold out!"